Primary aldosteronism: experience with thirty-eight patients.

Thirty-eight hypertensive, hypokalemic patients underwent adrenalectomy for primary aldosteronism. Thirty-one patients were found to have an adenoma and seven patients "idiopathic" hyperplasia. The diagnosis was made by finding low plasma renin activity, which could not be stimulated, and unsuppressable elevated plasma or urine aldosterone. The distinction between adenoma and hyperplasia and the localization of an adenoma were accomplished by adrenal venography, adrenal vein blood analysis, and iodocholesterol scanning. Venography was accurate in 87%; adrenal vein blood analysis in 91%; and iodocholesterol scanning in 72%. Dexamethazone suppressed scanning heightened discrimination to 91%. The adenomas were equally distributed between the right and left adrenal gland, with one patient having bilateral adenomas. All but two patients underwent adrenalectomy from a posterior lumbar incision. Postoperative recovery was uncomplicated. Eighteen months after operation 77% of patients with an adenoma were normotensive.